Aneurysm devices with additional anchoring mechanisms and associated systems and methods

ABSTRACT

The present technology relates to aneurysm devices with additional anchoring mechanisms, and associated systems and methods. In some embodiments, the aneurysm devices are endovascularly deliverable to a site proximate an aneurysm near a parent artery with bifurcating branches. The aneurysm devices can include a closure structure ( 102 ) comprising a distal-facing aspect configured to at least partially occlude the aneurysm and a proximal-facing aspect configured to arch over lumina of the bifurcating branches. The devices further include a supplemental stabilizer ( 103 ) connected to the closure structure. The supplemental stabilizer is configured to reside in the parent artery. The closure structure includes a hinge point ( 175 ) where the closure structure folds to form a loop element configured for anchoring within at least one of the bifurcating branches.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of pending U.S. ProvisionalPatent Application No. 61/493,356, filed on Jun. 3, 2011, andincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present technology relates to implantable therapeutic devices at atarget site, such as an opening at a neck of an aneurysm. In particular,the present technology is generally directed to aneurysm devices withadditional anchoring mechanisms and associated systems and methods.

BACKGROUND

Many of the currently available surgical approaches for closing openingsand repairing defects in anatomical lumens and tissues (e.g., bloodvessels), septal defects, and other types of anatomical irregularitiesand defects are highly invasive. Surgical methods for clipping brainaneurysms, for example, require opening the skull, cutting or removingoverlying brain tissue, clipping and repairing the aneurysm from outsidethe blood vessel, and then reassembling tissue and closing the skull.The risks related to anesthesia, bleeding, and infection associated withthese types of procedures are high, and tissue that is affected duringthe procedure may or may not survive and continue functioning.

Minimally invasive techniques for treating aneurysms are accordinglyhighly desirable. In general, the minimally invasive therapeuticobjective is to prevent material that collects or forms in the aneurysmcavity from entering the bloodstream and to prevent blood from enteringand collecting in the aneurysm. This is often accomplished byintroducing various materials and devices into the aneurysm. Forexample, implantable vaso-occlusive metallic structures are well knownand commonly used. Many conventional vaso-occlusive devices have helicalcoils constructed from a shape memory material or noble metal that formsa desired coil configuration upon exiting the distal end of a deliverycatheter. The function of the coil is to fill the space formed by ananatomical defect and to facilitate the formation of an embolus with theassociated allied tissue. Multiple coils of the same or differentstructures may be implanted serially in a single aneurysm or othervessel defect during a procedure. Implantable framework structures arealso used in an attempt to stabilize the wall of the aneurysm or defectprior to insertion of filling material such as coils.

It is crucial to accurately implant such vaso-occlusive devices withinthe internal volume of a cavity and to maintain the device within theinternal volume of the aneurysm. Migration or projection of avaso-occlusive device from the cavity may interfere with blood flow ornearby physiological structures and poses a serious health risk. Inaddition to the difficulties of delivering implantable occlusiondevices, some types of aneurysms are challenging to treat because ofstructural features of the aneurysm or because of particularities of thesite. Wide-neck aneurysms, for example, are known to present particulardifficulty in the placement and retention of vaso-occlusive coils.Aneurysms at sites of vascular bifurcation are another example where theanatomical structure poses challenges to methods and devices that areeffective in treating the typical sidewall aneurysms. It is thereforechallenging to position conventional implantable devices duringdeployment, prevent shifting or migration of such devices afterdeployment, and preserve blood flow in neighboring vessels followingafter deployment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of an aneurysm device configured in accordancewith an embodiment of the technology.

FIG. 2 is a side view of the aneurysm device of FIG. 1 in a partiallydeployed configuration.

FIG. 3 is a view of the aneurysm device of FIGS. 1 and 2 deployed at theneck of an aneurysm and lodged at the bifurcated side artery branches.

DETAILED DESCRIPTION

The present disclosure describes implantable therapeutic devices andmethods for endovascular placement of devices at a target site, such asan opening at a neck of an aneurysm. In particular, selected embodimentsof the present technology are directed to devices having additionalanchoring mechanisms for lodging at bifurcated branches at the neck ofthe aneurysm. The following description provides many specific detailsfor a thorough understanding of, and enabling description for,embodiments of the disclosure. Well-known structures, systems, andmethods often associated with aneurysm treatment systems have not beenshown or described in detail to avoid unnecessarily obscuring thedescription of the various embodiments of the disclosure. In addition,those of ordinary skill in the relevant art will understand thatadditional embodiments may be practiced without several of the detailsdescribed below.

FIGS. 1 and 2 illustrate an embodiment of an aneurysm device 150configured in accordance with the present technology. In particular,FIG. 1 is a top plan view of the aneurysm device 150 in a substantiallyflat, pre-assembled configuration, and FIG. 2 is a side view of theaneurysm device 150 in a deployed configuration. Referring to FIG. 1,the aneurysm device 150 can comprise a closure structure 102 and asupplemental stabilizer or support 103 extending from the closurestructure 102. The closure structure 102 can be a frame, scaffold, orother structure that at least partially occludes the neck of an aneurysmto prevent embolic coils or other coagulative material within theaneurysm from escaping into the bloodstream. The closure structure 102includes a perimeter support 160 and an inner support 170. The perimetersupport 160 and inner support 170 can be joined at junctions 162 and164. The supplemental stabilizer 103 is shown in an unassembled stage inFIG. 1. Once assembled, the proximally extending sides of the closurestructure 102 and the supplemental stabilizer 103 hold the curvedportion of the closure structure 102 at the neck of the aneurysm.

The aneurysm device 150 can have struts 180 a-d projecting proximallyfrom the junctions 162 and 164. Struts 180 a and 180 c can be connectedat junction 162 and struts 180 b and 180 d are connected at junction 164to form the supplemental stabilizer 103 with proximal anchoringsegments. In one embodiment, the struts 180 a-d each include a hingepoint or bend point 175 a-d. The hinge points 175 a-d define collapsepoints and allow the struts 180 a-d to preferentially fold down in amanner that forms additional supporting elements for the aneurysm device150 that can be lodged in side artery branches at an aneurysm neck.

In the embodiment illustrated in FIG. 1, the aneurysm device 150 isconstructed from a substantially flat substrate by cutting, etching,stamping, or otherwise forming the framework of the closure structure102, the unassembled supplemental stabilizer 103, and the hinge points175 a-d. The closure structure 102 and the supplemental stabilizer 103can be constructed from a flat sheet of material having substantiallyuniform thickness, but in other embodiments different regions of thesheeted material can have different thicknesses corresponding to thedesired thickness for portions of the closure structure 102 and/or thesupplemental stabilizer 103. Further, in other embodiments the aneurysmdevice 150 may be formed using different techniques and/or materials.

FIG. 2 is a side view of the aneurysm device 150 in a partially deployedconfiguration. In particular, as the aneurysm device 150 is deployedfrom a delivery catheter 202, loop elements 185 a and 185 b form andbegin to fully open. The loop elements 185 a-b start to open as thedelivery catheter 202 is being withdrawn and fully open when thedelivery catheter 202 is fully withdrawn. As described in greater detailbelow with reference to FIG. 3, the loop elements 185 a-b are configuredto provide a mechanism for the aneurysm device 150 to anchor inbifurcated side branches when deployed across the neck of an aneurysm.In other embodiments, the loop elements 185 a-b can have a differentarrangement and/or the aneurysm device 150 may include a differentnumber of loop elements 185.

FIG. 3 illustrates the aneurysm device 150 of FIGS. 1 and 2 deployed atthe neck of an aneurysm A with anchoring legs 240. As mentioned above,when the aneurysm device 150 is deployed, the loop elements 185 a-b openand can lodge in side branch vessels SB1 and SB 2, respectively. Thelodging of the loop elements 185 a-b within the side branch vessels SB 1and SB 2 is expected to provide additional anchoring mechanisms for theaneurysm device 150 at the aneurysm A, and is expected to provide moresecured lodging/deployment of the aneurysm device 150.

FIG. 3 additionally illustrates the use of the aneurysm device 150 toretain debris and/or other materials, such as an embolic coil mass 250,within the aneurysm cavity. In one embodiment, for example, implantabledevices of the present technology may be deployed to retain debrisand/or previously placed materials within the aneurysm cavity. Inanother embodiment, implantable devices of the present technology may bedeployed before placing materials, such as embolic materials, coils, andthe like, in the aneurismal cavity, and then the materials may be placedthrough the openings in the closure structure. In this situation, theaneurysm device may be retracted following placement of the embolicmaterials, or it may be detached and left at the site.

EXAMPLES

1. An aneurysm device endovascularly deliverable to a site proximate anartery with bifurcating branches, the aneurysm device comprising:

-   -   a closure structure comprising a distal-facing aspect configured        to at least partially block an opening to the aneurysm and a        proximal-facing aspect configured to arch over lumina of the        bifurcating branches; and    -   a supplemental stabilizer connected to the closure structure,        the supplemental stabilizer configured to reside in the artery;    -   wherein the closure structure includes a hinge point at which        the closure structure folds to form a loop element configured        for anchoring within at least one of the bifurcating branches.

2. The aneurysm device of example 1 wherein the closure structurecomprises struts.

3. The aneurysm device of example 2 wherein the hinge point is formed onone of the struts.

4. The aneurysm device of example 1 wherein the closure structurecomprises four hinge points.

5. The aneurysm device of example 1 wherein the closure structure istransformable between a compressed configuration and a deployedconfiguration.

6. The aneurysm device of example 5, further comprising a catheterconfigured to retain the closure structure in the compressedconfiguration.

7. The aneurysm device of example 1 wherein the closure structurecomprises two loop elements, each individual loop element configured tolodge in one of the bifurcating branches.

8. The aneurysm device of example 1 wherein the closure structurecomprises a shape memory material.

9. A system for treating an aneurysm, the system comprising:

-   -   a distal framework portion comprising a distal-facing aspect        configured to enclose the aneurysm, wherein the distal framework        includes a plurality of struts, and wherein individual struts        include a hinge point; and    -   a proximal support framework connected to the distal framework        portion, the support framework configured to reside in the        parent artery and biased to press outward against a luminal wall        thereof 10. The system of example 9, further comprising a        delivery sheath configured to temporarily retain the distal        framework in a compressed configuration.

11. The system of example 9 wherein the struts comprise a generallyflexible material that preferentially bends at the hinge point.

12. The system of example 9 wherein the individual struts comprise aloop shape that bends at the hinge point.

13. The system of example 9 wherein the distal framework portion isformed from a generally flat, unassembled component into athree-dimensional, assembled component.

14. A method of treating an aneurysm located at a site proximate to aparent artery that bifurcates into downstream branches, the methodcomprising:

-   -   expanding an axially-compressed framework comprising a distal        portion and a proximal portion at a site proximate to the        aneurysm, wherein the distal portion comprises a plurality of        struts having bend points; and    -   arching the distal portion of the framework unobtrusively over        lumina of the downstream branches, wherein the struts comprise        loops bent at the bend points, the loops configured to lodge in        the downstream branches.

15. The method of example 14, further comprising forming the frameworkfrom a substantially flat material.

16. The method of example 14, further comprising delivering theframework to the site with a catheter, wherein delivering the frameworkcomprises temporarily restraining the framework in a generallycompressed configuration.

17. The method of example 14, further comprising extracting theframework from the parent artery.

18. The method of example 17 wherein extracting the framework comprisesrestraining the framework in a catheter in a generally compressedconfiguration.

19. The method of example 14, further comprising substantially enclosingthe aneurysm with the distal portion of the framework.

20. The method of example 14, further comprising detaching the frameworkfrom a delivery device.

The above detailed descriptions of embodiments of the technology are notintended to be exhaustive or to limit the technology to the precise formdisclosed above. Although specific embodiments of, and examples for, thetechnology are described above for illustrative purposes, variousequivalent modifications are possible within the scope of thetechnology, as those skilled in the relevant art will recognize. Forexample, while steps are presented in a given order, alternativeembodiments may perform steps in a different order. The variousembodiments described herein may also be combined to provide furtherembodiments. In particular, the clot removal devices described abovewith reference to particular embodiments can include one or moreadditional features or components, or one or more of the featuresdescribed above can be omitted.

From the foregoing, it will be appreciated that specific embodiments ofthe technology have been described herein for purposes of illustration,but well-known structures and functions have not been shown or describedin detail to avoid unnecessarily obscuring the description of theembodiments of the technology. Where the context permits, singular orplural terms may also include the plural or singular term, respectively.

Moreover, unless the word “or” is expressly limited to mean only asingle item exclusive from the other items in reference to a list of twoor more items, then the use of “or” in such a list is to be interpretedas including (a) any single item in the list, B all of the items in thelist, or (c) any combination of the items in the list. Additionally, theterm “comprising” is used throughout to mean including at least therecited feature(s) such that any greater number of the same featureand/or additional types of other features are not precluded. It willalso be appreciated that specific embodiments have been described hereinfor purposes of illustration, but that various modifications may be madewithout deviating from the technology. Further, while advantagesassociated with certain embodiments of the technology have beendescribed in the context of those embodiments, other embodiments mayalso exhibit such advantages, and not all embodiments need necessarilyexhibit such advantages to fall within the scope of the technology.Accordingly, the disclosure and associated technology can encompassother embodiments not expressly shown or described herein.

1. An aneurysm device endovascularly deliverable to a site proximate anartery with bifurcating branches, the aneurysm device comprising: aclosure structure comprising a distal-facing aspect configured to atleast partially block an opening to the aneurysm and a proximal-facingaspect configured to arch over lumina of the bifurcating branches; and asupplemental stabilizer connected to the closure structure, thesupplemental stabilizer configured to reside in the artery; wherein theclosure structure includes a hinge point at which the closure structurefolds to form a loop element configured for anchoring within at leastone of the bifurcating branches.
 2. The aneurysm device of claim 1wherein the closure structure comprises struts.
 3. The aneurysm deviceof claim 2 wherein the hinge point is formed on one of the struts. 4.The aneurysm device of claim 1 wherein the closure structure comprisesfour hinge points.
 5. The aneurysm device of claim 1 wherein the closurestructure is transformable between a compressed configuration and adeployed configuration.
 6. The aneurysm device of claim 5, furthercomprising a catheter configured to retain the closure structure in thecompressed configuration.
 7. The aneurysm device of claim 1 wherein theclosure structure comprises two loop elements, each individual loopelement configured to lodge in one of the bifurcating branches.
 8. Theaneurysm device of claim 1 wherein the closure structure comprises ashape memory material.
 9. A system for treating an aneurysm, the systemcomprising: a distal framework portion comprising a distal-facing aspectconfigured to enclose the aneurysm, wherein the distal frameworkincludes a plurality of struts, and wherein individual struts include ahinge point; and a proximal support framework connected to the distalframework portion, the support framework configured to reside in theparent artery and biased to press outward against a luminal wallthereof.
 10. The system of claim 9, further comprising a delivery sheathconfigured to temporarily retain the distal framework in a compressedconfiguration.
 11. The system of claim 9 wherein the struts comprise agenerally flexible material that preferentially bends at the hingepoint.
 12. The system of claim 9 wherein the individual struts comprisea loop shape that bends at the hinge point.
 13. The system of claim 9wherein the distal framework portion is formed from a generally flat,unassembled component into a three-dimensional, assembled component. 14.A method of treating an aneurysm located at a site proximate to a parentartery that bifurcates into downstream branches, the method comprising:expanding an axially-compressed framework comprising a distal portionand a proximal portion at a site proximate to the aneurysm, wherein thedistal portion comprises a plurality of struts having bend points; andarching the distal portion of the framework unobtrusively over lumina ofthe downstream branches, wherein the struts comprise loops bent at thebend points, the loops configured to lodge in the downstream branches.15. The method of claim 14, further comprising forming the frameworkfrom a substantially flat material.
 16. The method of claim 14, furthercomprising delivering the framework to the site with a catheter, whereindelivering the framework comprises temporarily restraining the frameworkin a generally compressed configuration.
 17. The method of claim 14,further comprising extracting the framework from the parent artery. 18.The method of claim 17 wherein extracting the framework comprisesrestraining the framework in a catheter in a generally compressedconfiguration.
 19. The method of claim 14, further comprisingsubstantially enclosing the aneurysm with the distal portion of theframework.
 20. The method of claim 14, further comprising detaching theframework from a delivery device.